In the design and construction of sandals for informal wear, it is common practice to use various kinds of material to give a soft, comfortable feel to the sandal when worn. In the past, the soles of such sandals have been made of foamed plastic, of wood, and of all types of available materials. Most of these materials, however, have had draw-backs. In the case of wood, for instance, the sandal becomes fairly heavy is easily destroyed by exposure to weather and salt water; furthermore, it is expensive to manufacture. Foamed plastic, on the other hand, is easily made dirty and absorbs perspiration; furthermore, it has a tendency to remain wet after exposure to water. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a sandal having a shape which conforms to the human foot and has a spring-like feel while walking.
Another object of this invention is the provision of a sandal which is easily dried when exposed to water and is easily kept clean due to having an impervious surface.
A further object of the present invention is the provision of a sandal in the form of a hollow plastic element which is simple in construction, which is inexpensive to manufacture from readily-obtainable materials, and which is capable of a long-life of useful service with a minimum of care.
It is another object of the instant invention to provide a sandal having a hollow plastic whose color can be easily selected and changed during manufacture.
A still further object of the invention is the provision of a apparatus and method for forming a sandal having a hollow sole and by which is possible to manufacture the sole with a slight positive air pressure within.